QUIZ: No. 33, 01/11/2025

MRI

MRI

ANS – Vulval angiomyofibrobalstoma (Mesenchymal tumor)

Findings: Well-defined, lobulated soft-tissue lesion in the right anterior perineum involving the labia majora. The lesion appeared isointense to mildly hypointense on T1-weighted images and heterogeneously hyperintense on T2/STIR sequences with the presence of internal septations. Post-contrast images demonstrated heterogeneous enhancement with multiple fine vascular channels within the lesion. There was no evidence of infiltration into the adjacent pelvic or perineal muscles, and no pelvic or inguinal lymphadenopathy was noted. Suggestive of benign mesenchymal tumor

Ø  Angiomyofibroblastoma is a benign mesenchymal tumor of the vulvovaginal region, typically seen in middle-aged women

Ø  Aggressive angiomyxoma: Large, poorly defined infiltrative mass with marked T2 hyperintensity, characteristic “swirl sign,” and progressive heterogeneous post-contrast enhancement extending into deep pelvic soft tissues.

Ø  Cellular angiofibroma: Well-circumscribed solid lesion with intermediate T1 and heterogeneously iso- to hypointense T2 signal, showing homogeneous enhancement and minimal vascularity without infiltration.

Ø  Management - Local excision is curative, and recurrence is extremely rare.

Take home points

Signal characteristics and enhancement pattern on MRI provide valuable clues to the tumor’s myxoid and vascular components to differentiate angiomyofibroblastoma from infiltrative aggressive angiomyxoma.